The Vikings have had some great safeties over the years, such as Hall of Famer Paul Krause, who came to the Vikings in a great trade with the Redskins back in 1968, first-round draft choice Joey Browner, Robert Griffith and Darren Sharper, who became a Viking after being a longtime Packer.

I have followed the Vikings closely since their inception. And I'm confident no Vikings safety has had as good of a rookie year as first-round pick Harrison Smith.

He is one of the big reasons the Vikings are much improved defensively.

Smith has made some great plays this year, but none more important than the touchdown he scored on an interception Sunday that was the margin of victory over a stubborn Arizona team.

Smith's grab and go gave the Vikings a 21-7 lead in the third quarter and allowed them the cushion needed to hold off Arizona.

The Cardinals dominated the Vikings statistically. They had 356 yards of offense to the Vikings' 209 and won the battle of possession, 35:05 to 24:55 and limited the home team to one first down in the fourth quarter.

Vikings coach Leslie Frazier sang the praises of Smith when he said, "He's having a fantastic rookie year. That play he made [Sunday] was a great play and then the run after the catch. He's a smart football player, a tough football player; he's been great for our defense.

"He should have a bright future. I think he's going to be a good football player for a long time. The fact that he's a smart player, he studies, he works extremely hard, and he has very good hands. He's a bright player who is very athletic and talented.

"Along with a lot of our other guys, he's helped our defense improve."

Came in trade

The Vikings fell in love with Smith while the coaching staff was working at the Senior Bowl, and as they approached draft day they were determined to find a way to trade for him knowing they were going to take Southern California tackle Matt Kalil with their first-round pick. They had to find a way to trade for another first-round pick to get Smith, who they believed they had to have.

"We talked to probably 10 or 11 teams, everyone drafting after 20," Vikings General Manager Rick Spielman said. "Our guys liked him. We knew about him when he was at Notre Dame, and the Senior Bowl just solidified everything we knew.

"I didn't know if he would be there by the time we picked the next day in the second round. We called a lot of teams on the bottom end and were able to make that trade."

The move to get Smith actually began when the Vikings traded the third overall pick in the first round to Cleveland for the No. 4 pick -- which they used on Kalil -- and fourth-, fifth- and seventh-round picks. The Vikings then had the flexibility to trade their second-round pick and a fourth-rounder to Baltimore so they could move up and select Smith at No. 29 in the first round.

Smith never had returned an interception for a touchdown at Notre Dame, and this was his first interception and first touchdown in the NFL.

"I got in the end zone and I was just excited," he said when asked about his reaction to the score. "I wasn't thinking anything, I was just excited. Then I realized we had to get back on the defense, so I calmed down."

Because of Smith and others who have contributed so much, like outstanding first-year kicker Blair Walsh and developing cornerback Josh Robinson, this could be one of the best drafts in the Vikings history.

Big recovery

It was Matt Asiata who recovered the onside kick late in the fourth quarter to lock up the victory.

There was 1:38 left and the Cardinals had just cut the Vikings lead to 21-14 when Asiata made the play. At that point the Cardinals offense was rolling, and had they recovered the onside kick and gotten the ball near their own 43, there was a chance the game would have gone into overtime.

Asiata is a great story. Going undrafted out of the University of Utah, the running back was released by the Vikings once and then called back again this year and has stuck with the team -- playing on several special teams units.

The onside kick recovery was the first of his career.

"I have no idea who was close to me," Asiata said. "All I saw was the ball, and my first instinct was to get on it and stay on it and not move an inch, just squeeze the hell out of the ball."

Asiata has just two rushes for 8 yards this season and one reception for 2 yards. Modest statistics, but he had a terrific preseason, including a nine-carry, 48-yard performance in a loss at San Diego and a seven-carry, 43 yard performance in a victory over Buffalo, so he has shown he can perform when given the chance.

"The thing that the coaches harp on, if you can't make the role on offense or whatever, then special teams is the main goal to make the team,'' Asiati said. ''Special teams has been there, I love special teams, I didn't play them in my college career, but it's a big role, a big step for me. I want to be there for the team and make the squad."

Winfield had big day

Larry Fitzgerald, the former Holy Angels High School star now widely considered the best receiver in the NFL, had just seven passes thrown to him Sunday, and he caught four for just 29 yards. It was a great defensive job on him, primarily by Vikings veteran cornerback Antoine Winfield.

"I mean Larry's a great player. Sometimes we had to double him, sometimes the D-line had a great rush and we singled up and he didn't have time to uncover," Winfield said.

"That was the game plan; we were going to try to take him out and make somebody else beat us."

Winfield is very impressed with Fitzgerald.

"He has it all, great route runner, great size, great hands. I played against him a couple of times. He's always a threat once he's on the field.

"He made some plays but that's the league; he gets paid a lot of money to do that."

Fitzgerald complimented the Vikings' game plan.

"[They] do a really good job once they get a lead on you," Fitzgerald said. "Leslie Frazier and his staff are going to play Cover 2, they are going to make you dink and dunk, they are going to make you play underneath, they are going to come up and tackle. ... We knew that coming in, they did exactly what we anticipated them doing."

Sid Hartman can be heard weekdays on 830-AM at 6:40, 7:40 and 8:40 a.m. and on Sundays at 9:30 a.m. shartman@startribune.com